international workshop for godar westpac global ocean data archeology and rescue: scientific needs...
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International Workshop for GODAR WESTPAC
Global Ocean Data Archeology and Rescue:
Scientific Needs from the Carbon Cycle Study in the Ocean
Toshiro Saino
Hydrospheric Atmospheric Research Center, Nagoya Universityand
Hydrographic Department, Japan Coast Guard
05 Mar 2002 @HD/JCG
International Workshop for GODAR WESTPAC
Oceanographic Data are
- taken on site aboard ships.- Precious and Expensive.- containing “Facts” at the time of the observation.- obtained with methods varying with time, group, etc., and hence meta data are important.- suffering from under-sampling problem.
International Workshop for GODAR WESTPAC
Under Global Climate Change Carbon Cycle in the Oceans is an important part of the Life Support System of the Planet Earth. Prediction of Variability is required.
In Old Good Days Most Carbon Cycle Studies were to get mechanistic understanding of the processes. And Qualitative, or semi-quantitative, description of the system was obtained.
International Workshop for GODAR WESTPAC
International Workshop for GODAR WESTPAC
International Workshop for GODAR WESTPAC
Future Research on Biological and Chemical Aspectsof Global Change in the Ocean (Ocean Future)
Issue 1: What controls the time-varying biogeochemical state of the ocean system and how will itchange in response to Global Change?
Issue 2: How will marine food webs respond to Global Change?
Issue 3: How does the accumulation of carbon in the ocean respond to global environmental change?
International Workshop for GODAR WESTPAC
Key Words:ecosystem response and feedback to Climate Changetemporal and spatial variabilitycoastal region and human activityquantitative estimation and/or prediction
Needs:Globally networked High Frequency & Long Term Time Series
Observations.Historical Data Sets for Variability longer than Decadal Time Scale.
Wind stress1950-1990
Long term change in lower trophic level environments in theWestern subtropical Pacific Gyre
100
15 0
200
25 0
ML
D (
m)
0 .05
0 .10
0 .15
0 .20
Win
d s
tres
s (N
/m2 )
r = 0 .72
5 0 5 3 5 6 5 9 6 2 6 5 6 8 7 1 7 4 7 7 8 0 8 3 8 6 8 9 9 2 9 5 9 8
Y ea r (1 9 0 0 + )
0 .05
0 .1 0
0 .15
0 .20
Win
d s
tres
s (N
/m2 )
- 8
- 4
0
4
8
MO
I in
dex
(m
b)r = 0 .7 3
Long term change in lower trophic level environments in theWestern subtropical Pacific Gyre
Variation of Surface Mixed Layer, Wind Stress and Monsoon Index in Winter
The winter MLD varies with wind stress
0 .5
1 .0
1 .5
ML
N (
uM
)
150
200
250
ML
D (
m)W in ter
7 0 7 3 7 6 7 9 8 2 8 5 8 8 9 1 9 4
Y ea r (1 9 0 0 + )
3 0
4 0
5 0
6 0
(mg/
m-2
)
W in ter
S p rin g
T ota l ch l a (0 -200 m )
Deeper MLD ＞ Higher Nitrate ＞ Lower Chl a in winter ＞ Higher Chl a in spring
Stronger Wind
Increased Productivity
Standing StocksFlux Flux
Long term change in lower trophic level environments in theWestern subtropical Pacific Gyre
Variation of MLD, Nitrate, and Chl in winter and Chl in spring
0 .0
0 .5
1 .0
1 .5M
LN
(u
M)
150
200
250
ML
D (
m)
W in ter
0 .05
0 .10
0 .15
0 .20
0 .25
ML
P (
uM
)
M L N
M L DM L P
M u rp h y an d R iley 's m eth o d
7 0 7 3 7 6 7 9 8 2 8 5 8 8 9 1 9 4
Y ea r (1 9 0 0 + )
4 0
5 0
6 0
7 0
(mg/
m2 )
W in terT o ta l ch l a (0 -2 0 0 m )
Different behavior of Nitrate and Phosphate. What happened?
Long term change in lower trophic level environments in theWestern subtropical Pacific Gyre
Variation of MLD, Nitrate, Phosphate and Chl in winter
Long term change in lower trophic level environments in theWestern subtropical Pacific Gyre
Ecosystem Change in the Eastern Tropical Pacific Gyre (Results from HOT observation: D.M.Karl)
Appearance of Nitrogen fixer shifted Ecosystem from N-limited to P-limited
N P ra tio s v e rsu s d en s ity
Appears only in 1980s in the Subtropical Mode WaterNitrogen Fixation? Why is it returned?
Long term change in lower trophic level environments in theWestern subtropical Pacific Gyre
Frequency of NO3/PO4 >16 waters appearance (upper) and water densityof its appearance (bottom): Left; winter, Right; spring
Long term change in AOU and nutrients in the western subarctic Pacific
Microbial Loop dominance
Grazing Chain dominance
PM lineSts. 4,5,6
polar front
Fig. 1
Ecosystem change in the Japan Sea 70s - 90s
CO2From..
To
DOM
CO2
Year (+1900)
-40
-20
0
20
40
73 75 77 79 81 83 85 87 89 91 93 95 97 99
-3-2-10123
Chl aDiatom cell
Chl
a (
mg
m-2)
Lo
g10
(cell l -1+
1)
WT
(C
)
0 m100 m200 m
-4
-2
0
2
4
Fig.2 Water temperature anomaly at 3 depth
PO4
-40
-20
0
20
40
-0.1
0
0.1
Chl
a (
mg
m-2)
PO
4 (µM
)
Chl a
Fig. 3 MLD mean PO4 and Chl a
Fig. 4 Diatom cell number and Chl a
Water stratification enhanced
Phytoplanktonquality change(small, less nutritious cell)
Nutrients depletionearlier in spring
What happened in 80s?
Food webStructure
change?
5 seasons running mean
spring
spring